Risk assessment of Phlyctinus callosus for the EU

Area of Science:

• Agricultural Entomology
• Quantitative Risk Assessment
• Invasive Species Biology

Background:

• Phlyctus callosus (P. callosus) is a polyphagous pest originating from Australia, New Zealand, and South Africa.
• The European Commission requested a quantitative risk assessment for P. callosus within the EU.
• Previous assessments did not comprehensively evaluate the EU-wide risk of this pest.

Purpose of the Study:

• To conduct a quantitative risk assessment for Phlyctus callosus in the EU.
• To identify potential entry pathways, establishment conditions, spread capacity, and impact over a 10-year horizon.
• To inform risk management strategies for preventing P. callosus introduction and establishment.

Main Methods:

• Quantitative risk assessment modeling.
• Analysis of pest occurrence data and pathways (apples, cut flowers, table grapes).
• Climatic suitability modeling for establishment and spread prediction.

Main Results:

• Import of table grapes identified as the highest risk entry pathway.
• Median estimate of 49.5 potential P. callosus founder populations annually.
• Estimated median establishment of 1 founder population every 1.3 years under broader climatic conditions.
• Projected spread rate of 15.5 m/year after a 4.0-year lag phase.
• Potential production losses: 0.5% for cut flowers, 5.2% for apples, 2% for table grapes.

Conclusions:

• Phlyctus callosus poses a considerable risk to EU agriculture, particularly table grape production.
• The risk is driven by import pathways, establishment probability, and pest spread.
• Further research on risk reduction measures is warranted to mitigate potential economic impacts.